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Lepidoptera

Cecropia Moths Pupating

11-11-13 cecropia cocoon dissected  056Our largest North American native moth, the Cecropia Moth, Hyalophora cecropia, spends the winter as a pupa inside a cleverly-crafted 3” – 4”-long shelter, or cocoon, which it creates and attaches lengthwise to a branch while still in its larval stage. The Cecropia caterpillar, with the silk glands located near its mouthparts, spins not one, but two silk cases, one inside the other. In between the two cases, it spins many loose strands of very soft silk, presumably to enhance the insulating properties of the cocoon. Inside the inner case, the caterpillar splits its skin and transforms into a pupa. Come spring, an adult moth will emerge from the pupal case and exit the cocoon through one end which was intentionally spun more loosely, allowing the moth to crawl out the somewhat flexible tip. (Note: dissected cocoon was not viable.)

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Apple Scat

10-4-13 woolly bear scat 028At this time of year it’s not unusual to find the scat of various mammals consisting mostly of apple. Red Foxes, White-tailed Deer, Cottontail Rabbits, Porcupines and Black Bears, in particular, are all avid consumers of this appetizing fruit. Birds, including Purple Finches, Cedar Waxwings and Northern Mockingbirds, also include apples in their diets . While many insects drink the juice of apples, it’s not that often you see an insect like this Woolly Bear caterpillar (the larval stage of the Isabella Tiger Moth) consuming a sizable chunk of a McIntosh apple and leaving behind tell-tale scat. (Discovery by Sadie Richards)

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Black Swallowtail Larvae Soon to Form Chrysalises

8-29-13 black swallowtail larva and QALace 028In its younger days, this Black Swallowtail larva resembled a bird dropping, but in successive molts a green (or white), yellow and black pattern develops. Often discovered in vegetable gardens on carrot, parsley and dill plants, it also feeds on wild members of the carrot/parsley family (Apiaceae), including its favorite, Queen Anne’s Lace (pictured). Seeds as well as leaves are rapidly consumed, as the time for one last molt and the development of a chrysalis in which to overwinter approaches.

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Butterflies Obtain Nutrients From Scat

8-14-13 white admiral on raccoon scat 019Nectar from flowers and sugar from running sap (especially at Yellow-bellied Sapsucker holes) or overripe fruit provide most, but not all, of the nutrition that butterflies need. The males of some species will also drink at muddy puddles or damp earth for mineral salts and on scat or animal carcasses to get amino acids and other vital nutrients. This added nutrition is needed for them to generate spermatophores, the packets of sperm and nutrients that are transferred to the female during mating. (Photo is of a White Admiral, Limenitis arthemis arthemis, feeding on blackberry seed-laden Raccoon scat.)

Naturally Curious is supported by donations. If you choose to contribute, you may go to http://www.naturallycuriouswithmaryholland.wordpress.com and click on the yellow “donate” button.


Abbott’s Sphinx Moth Larva

7-26-13  Abbott's Sphinx Moth larva 066Abbott’s Sphinx Moth larvae feed on grape and Virginia creeper leaves during the night. During the day they tend to rest on the woody vines of the plants they are eating, and because they are well camouflaged, they remain hidden from most humans’ eyes. Both as larvae and adults, these moths are well equipped for survival. Older larvae have two color forms, one resembling unripe green grapes (in photo), and the other is brown and looks much like a branch. In their last stage, or instar, both forms have a rear eyespot which looks like a human eye, right down to the white reflection spot in it, which scares off potential predators. If the caterpillar is pinched or prodded, it squeaks and tries to bite the attacker. The adult moths, which emerge next summer after pupating all winter, also defend themselves with both color and behavior. They are brown with yellow bands on their underwings, which make them look something like a bumblebee, and when they fly, they create a buzzing noise. (Thanks to Heidi, Tom and Simmy Wetmore for photo op.)


Fritillaries Feeding

7-24-13    Atlantis Fritillary 627Greater Fritillaries are a genus of butterflies that are also known as “silverspots” due to the silver spots many of them have beneath their hind wings. Greater Fritillaries in New England include the Great Spangled Fritillary , the Aphrodite Fritillary and the Atlantis Fritillary. It can be challenging to tell these three orange-dappled species apart. The black margins on the upper side of the pictured Atlantis Fritillary’s wings help identify it. This fritillary is named after Atlantis, a legendary island first mentioned by Plato. While adult Atlantis Fritillaries favor the nectar of milkweed, thistle, burdock and boneset, the brown and black-speckled larvae feed on violets.


Monarch Numbers Down

7-22-13 monarch IMG_1107According to the Vermont Center for Ecostudies, this spring and summer there’s been an estimated drop of 90% in the overall monarch population in eastern Canada – the most dramatic decline ever recorded. Vermont (and most likely New England in general) is experiencing much the same situation. The low numbers of monarchs are due to several factors that they have encountered along their migratory routes the past couple of years, including extreme temperatures, record drought, low nectar production by flowering plants and a scarcity of their host plant, milkweed. The cold temperatures and record amounts of rain this spring undoubtedly added to their stress.


Moth Eyes and Biomimicry

7-1-13 luna eyes 020Because moths need to use every little bit of light available in order to see in the dark, their eyes are highly non-reflective. (This is also helpful in decreasing the chances of predators spotting them.) Scientists, through biomimicry, have come up with a number of technological advances, including the development of a film that can be applied to solar cells which helps keep sunlight from being reflected off of them before the light can be utilized. Man-made materials based on the structure of moth eyes could someday reduce the radiation dosages received by patients getting x-rayed, while improving the resolution of the resulting images. Research on recreating the pattern found on moths’ eyes onto plastic could lead to reflection and glare-free display screens for televisions, cell phones, computer monitors, eyeglasses, speedometers and more.


Caterpillar Survival Strategies

6-14-13 camouflaged catterpillar 049The larvae of moths and butterflies are very susceptible to predation, especially by birds, and they utilize many different strategies to protect themselves. Shapes, colors and behavior all contribute to their survival. Some larvae take on the appearance of less appetizing things, such as bird droppings, twigs or leaves. Some have large eye spots which presumably scare predators. Others have cryptic coloration which makes them all but invisible. The pictured green caterpillar uses both color and behavior to visually disappear on the fern it is consuming.


Butterflies Mating

6-10-13 mating pearl crescents 351These mating Pearl Crescent butterflies may have used size, color, shape, vein structure and/or pheromones to recognize each other. When mating, most male butterflies provide a package (spermatophore) of sperm and nutrients the female needs to produce and lay eggs. The mated female stores the spermatophore in a sac called a bursa until she’s ready to lay eggs. She fertilizes her eggs as she lays them, using the last sperm she received first. For this reason, males of some species will leave a substance that dries into a film on the female’s abdomen in an effort to keep her from mating with other males. (Thanks to Kent McFarland for butterfly i.d.)


Eastern Commas Flying

4-23-13 green comma IMG_9353Commas are a group of butterflies also known as anglewings (for obvious reasons). There are several species of commas in New England, all of which have a silver mark in the shape of a comma underneath each hind wing. Like mourning cloaks, these butterflies overwinter as adults in bark crevices, logs or other protected spots. You often see them in the woods, where they feed on tree sap, mud, scat and decaying organic matter. When perched with their wings closed, they are extremely well camouflaged and easily mistaken for a dead leaf.


A Great Christmas Present!

If you’re looking for a present for someone that will be used year round, year after year, Naturally Curious may just fit the bill.  A relative, a friend, your child’s school teacher – it’s the gift that keeps on giving to both young and old!

One reader wrote, “This is a unique book as far as I know. I have several naturalists’ books covering Vermont and the Northeast, and have seen nothing of this breadth, covered to this depth. So much interesting information about birds, amphibians, mammals, insects, plants. This would be useful to those in the mid-Atlantic, New York, and even wider geographic regions. The author gives a month-by-month look at what’s going on in the natural world, and so much of the information would simply be moved forward or back a month in other regions, but would still be relevant because of the wide overlap of species. Very readable. Couldn’t put it down. I consider myself pretty knowledgeable about the natural world, but there was much that was new to me in this book. I would have loved to have this to use as a text when I was teaching. Suitable for a wide range of ages.”

In a recent email to me a parent wrote, “Naturally Curious is our five year old’s unqualified f-a-v-o-r-I-t-e  book. He spends hours regularly returning to it to study it’s vivid pictures and have us read to him about all the different creatures. It is a ‘must have’ for any family with children living in New England…or for anyone that simply shares a love of the outdoors.”

I am a firm believer in fostering a love of nature in young children – the younger the better — but I admit that when I wrote Naturally Curious, I was writing it with adults in mind. It delights me no end to know that children don’t even need a grown-up middleman to enjoy it!


Bruce Spanworm Moths Flying

If you’ve walked in New England woods recently, chances are great that you’ve noticed light tan moths with a one-inch wing span flitting about — an odd sight for this late in the year. These are male Bruce Spanworm Moths (Operophtera bruceata), also called Winter Moths, as the adults are active from October to December. They belong to the Geometer family of moths, the second largest family of moths in North America, which includes many agricultural and forest pests. The males are seeking wingless, and therefore flightless, females to mate with. Eggs are laid in the fall, hatch in the spring, the larvae pupate in the summer, and emerge as adult moths in the fall. Bruce Spanworm larvae periodically defoliate hardwood trees, preferring the buds and leaves of sugar maple, American beech and trembling aspen trees.


Cecropia Moth Cocoon

This past summer there seemed to be more giant silkmoths than usual, including Cecropia Moths (Hylaphora cecropia).  (see http://naturallycuriouswithmaryholland.wordpress.com/2012/06/04/cecropia-moth-2/ ). Assuming many of these moths bred and laid eggs, and that most of the larvae survived, there are probably a large number of Cecropia cocoons in our woods.  Even so, it is not an easy task to find them, as they are so well camouflaged, and are often mistaken for a dead leaf.  Cecropia caterpillars spin silk and fashion it into a three-inch long, tan cocoon (giant silkmoths make the largest cocoons in North America) which they attach lengthwise to a branch or stem.  There is a tough but thin layer of silk on the outside, which protects an inner, thicker and softer layer of silk on the inside.  The caterpillar enters the cocoon through loose valves it makes in both layers, which are located at the tip of the cocoon’s pointed end.  Shortly after the larva crawls inside both of these layers, it pupates.  Its skin splits, revealing a dark brown pupa. For the rest of the winter and most of the spring, it remains a pupa.  In early summer it metamorphoses into an adult moth and exits the cocoon through the same valves  through which it entered.

 


Woolly Bears on the Move

Although it’s fun to try to predict the severity of the coming winter by the amount of brown on a woolly bear caterpillar (the more brown = the milder the coming winter, according to folklore), the coloration of any given woolly bear caterpillar has more to do with its diet and age than the coming weather.  The more a Woolly Bear eats, the more frequently it molts, and each time it molts a portion of the black hairs (setae) is replaced by brown ones.  A Woolly Bear can molt up to six times — the best fed and oldest woolly bears, which have molted the most number of times, have the widest brown bands. (After overwintering as caterpillars, Woolly Bears pupate and emerge as small, brown moths called Isabella Tiger Moths, Pyrrharctia isabella.)


Goldenrod Spindle Gall

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There are three fairly well-known galls (abnormal plant growths caused by a variety of organisms) on goldenrod – the goldenrod ball gall (round swelling in stem caused by a gall fly), the goldenrod bunch gall (leaves at top of plant are bunched up into a mass caused by a gall midge) and the goldenrod spindle gall (elliptical stem swelling caused by a moth).  The amazing thing about insect galls is that not only do they provide shelter for the insect, but they are nutritious and serve as the insect’s food supply as well.    The spindle-shaped galls are home to the larval stage of the goldenrod gall moth (Gnorimoschema gallaesolidaginis).  In the late fall the adult female moth lays an egg on a low goldenrod leaf, where it overwinters. The larva, or caterpillar, hatches out the following spring and makes its way from the now dead leaf to a newly sprouted goldenrod, where it eats its way through a bud and into the stem.  The goldenrod plant reacts to this activity by forming an elliptical swelling, or gall, around the area where the larva took up residence. The larva feeds and develops all summer.  Prior to pupating, it chews a tunnel all the way through the gall (this is the only stage in which the moth has chewing mouthparts), and then spins a silk cover for it.  The larva then returns to the cavity in the middle of the gall and pupates.  In the fall the adult moth crawls down the tunnel,  bursts through the thin layer of silk and then mates and lays eggs.


Yellow-shouldered Slug Moth

You could hardly be blamed for not recognizing that this bright yellow-green, half-inch-long, oval creature is the larval stage of a moth!  Possessing suction cups rather than prolegs, the Yellow-shouldered Slug (Lithacodes fasciola) glides, rather than crawls, over the leaf it is consuming.  Perhaps this is why these caterpillars show a preference for smooth-leaved trees and shrubs such as basswood, beech, cherry, maple and oak (although this particular individual was found on a witch-hazel leaf).  The Yellow-shouldered Slug pupates inside a cocoon all winter, and in the spring a small, brown moth emerges.


Giant Swallowtail Caterpillar Defenses

The Giant Swallowtail (Papilio crestphones) appears to be extending its range northward into Vermont.  It was first confirmed here two years ago, and more sightings have been made each summer since then.  The Giant Swallowtail is the largest butterfly in North America, with roughly a 4-6-inch wingspan. Because of the caterpillar’s preference for plants in the citrus family, this butterfly is generally is found further south.  However,  Prickly Ash (Zanthoxylum americanum) is found in northern New England, and it is a member of the citrus family.  With this food source, and increasingly warm winters, the Giant Swallowtail may be here to stay.  The larval stage, or caterpillar, is as, or more, impressive as the adult butterfly.  Its defense mechanisms have to be seen to be believed.  The caterpillar looks exactly like a bird dropping (it even appears shiny and wet), making it appear unpalatable to most insect-eaters.   As if that weren’t enough, when and if it is threatened, a bright red, forked structure called an osmeterium emerges from its “forehead” and a very distinctive and apparently repelling odor to insect-eaters, is emitted.


Monarch Butterfly Migration is Underway

Monarch Butterflies have begun migrating — the peak of their migration in Central Vermont/New Hampshire is September 3 – 15. Monarchs typically cycle through four generations during the breeding season. The final generation migrates to Mexico. Those individuals emerging in late summer live much longer than the Monarchs that are around in June and July (6-9 month life span vs. 6-8 weeks). This allows Monarchs in the East the time needed to migrate up to 3,000 miles (a trip that takes roughly two months) to central Mexico, live through the winter and to begin a return trip (making it only about halfway back), mating along the way. The succeeding generations of Monarchs continue the return trip back to New England, and with luck, the great (or great-great) grandchildren of the butterflies that are migrating to Mexico now will grace our milkweed patches next summer.


Hickory Tussock Moth

 

Most tussock moths, such as this Hickory Tussock Moth (Lophocampa caryae), are densely covered with hair-like structures called setae that bear microscopic barbs.  Many people are sensitive to these setae and get an itchy rash if they handle a Hickory Tussock Moth.   Even touching the cocoon of a tussock moth can cause irritation, as the setae are woven into it.  Many tussock moths display warning coloration with their black, white, red, orange or yellow setae.  What looks like two Hickory Tussock Moth larvae in the photograph is actually one adult caterpillar (left) and its shed skin (right).   You can find these larvae feeding on hickory, walnut, ash, oak and many other trees in the woods right now.  After spending the winter pupating in a cocoon in the leaf litter, a small spotted, tan moth emerges.


Clouded Sulphurs

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Sulphurs are a group of butterflies that are usually some shade of yellow, orange or white and have a wingspan between 1 ½ “ and 2 ½ “. The three species likely to be seen in New England are the Clouded Sulphur, the Orange Sulphur and the Pink-edged Sulphur. (Distinguishing one species of sulphur from another can be quite challenging.) Sulphurs always perch with their wings closed, and are commonly seen on flowers drinking nectar as well as puddling in muddy areas, where they obtain salts and other minerals.


American Lady Larva

The American Lady larva is very distinctive with its branched spines and white bands across its abdomen.  One of its favorite foods is Pussytoes, a member of the Aster family.  The larva feeds inside a shelter it makes by tying up several leaves with silk.  In the photograph, the larva has incorporated the flower heads of Pussytoes into its shelter.  Not only is the larva feeding and growing inside this 1 ½ ”-long  cavity, it also shed its skin.  To see an adult American Lady butterfly, go to http://naturallycuriouswithmaryholland.wordpress.com/2012/07/08/american-lady-common-milkweed-pollinia/ .  Soon after the larva forms a chrysalis and pupates, a butterfly emerges and starts its migration south for the winter.


Spined Soldier Bug

The Spined Soldier Bug is a predatory stink bug which preys on a variety of other insects (over 90 species), especially the larvae of butterflies, moths and beetles. It is one insect that farmers actually welcome, as it preys heavily on the larvae of the European corn borer, Mexican bean beetle, cabbage looper, Colorado potato beetle, flea beetles and many other crop pests. The adult Spined Soldier Bug has a prominent spine on each “shoulder.” It also has piercing-sucking mouthparts which it uses to impale prey and suck out their internal juices. The photograph shows a Spined Soldier Bug dining on the innards of a monarch caterpillar.


Viceroy Butterfly

The Viceroy Butterfly closely resembles the Monarch Butterfly, but is smaller, and has a black line that runs across the veins of its back wings, which the Monarch lacks. While Viceroys don’t contain the poisonous cardiac glycosides that Monarchs do, they do contain salicylic acid due to fact that the larvae feed on willows. This acid not only causes the Viceroy to taste bad, but makes whatever eats it sick. So not only do these two butterflies look alike, but they discourage predators in the same way. This is not a coincidence. The fact that they are both toxic if eaten and are preyed upon by some of the same predators has led to their similar appearance. This phenomenon is referred to as Müllerian mimicry, and essentially it means if two insects resemble each other, they both benefit from each other’s defense mechanism — should a predator eat one insect with a certain coloration and find it inedible, it will learn to avoid catching any insects with similar coloration.


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